@allmankind: Because it detects an incompatible file named "install.esd" (needed only for upgrade) ... But as you mentioned that your ISO should allow also full install, are you sure about that ?
So if yes, could you please tell me if in your "sources" folder (in your Windows 8.1 DVD or ISO) you have a file called "install.esd" and/or "install.wim" ? And which size are they ? Thanks.
I use an ISO file of 8.1. And yes, the ISO allows a full install, as that is what I do onto a clean HD (and have done from this ISO). And it comes up of as a menu choice... Full Install or Upgrade Install (although not sure why upgrade would appear when I am installing onto a clean HD). I just want to get rid of a lot of the M$ bloat and tweak some registry settings.
I'll have to get back to you on the size of the install.esd/install.wim the next time I try a winreducer run.